Screening Of Removing Nutritional Repression And High Producing Ligninases Mutant Of White Rot Fungi, Enzyme-production Characteristics And Used To Dye Decolorization

Recently, White Rot Fungi as a broad-spectrum bioremediation preparation has been taken seriously in the world. But because of the Ligninolytic enzyme which mainly acts to degradation is belong to secondary metabolites and stimulated by lacking nitrogen nutrients, and the pollutant environment most belongs to eutrophic environment which restricts the applying of bioremediation in the environmental pollution. In the meantime, the production of enzyme is hard to improve for the cell growths and enzyme synthesis is unsynchronized. So, for White Rot Fungi and its lignin-degrading enzymes are applying for industry and environmental governance earlier, which mostly ties in whether or noseriously to get the mutant that can produce the resistance of nutritional repression and highly efficient synthesis the lignin-degrading enzymes in the eutrophic conditions.In this paper, we chosed Phanerochaete chrysosporium which was the model strain of White Rot Fungi as the material, breeded the White Rot Fungi with the resistance of nutritional repression and high yield of Ligninolytic enzyme by UV mutagenesis, and researched the enzyme-production characteristics of the superior strain with the resistance of nutritional repression, determined the best process parameters and the influencing factors. Also further researched the mutant's decolorization of Congo red, acid fuchsin, naphthol green B and malachite green when it was cultured in the straw, wood flour or sugarcane bagasse. we obtain the following results:(1) We got a mutant strain PCu-9 which can efficient synthesis Ligninolytic enzyme and the cell growed quickly in the nitrogen sufficient conditions by the Breeding Selection of UV mutagenesis, it broke the restriction of the original strain which need nitrogen nutritional limintation, realized the cell growths and Ligninolytic enzyme synthesis is simultaneously.(2) We optimized the Breeding strain's medium components, the strain PCu-9 had the best enzyme activity when it had been cultured in the medium with Glucose 20g/L, Ammonium tartrate 2.2g/L, Tween 80 1g/L and Mn2+ 0.2g/L as the major components, and adding Benzyl alcoho 5.2mmol/L in the 1d .The culture condition of the best enzyme activity is T 37℃, initial pH4.5. when the strain PCu-9 was cultured in the above conditions for 6d under the static culture, the LiP activity of the Ligninolytic enzyme system could reached 2013.59U/L, improved 23.41% than the un-optimized strain; the MnP activity could reach 353.42U/L, improved 27.97% than the un-optimized strain.(3) When the Breeding was cultured in the solid-state fermentation medium of the straw, wood flour and sugarcane bagasse for 6d, decolorized the Congo red, acid fuchsin, naphthol green B and malachite green, the results showed that: The strain PCu-9 had the same decolorization efficiency as the original strain, both for naphthol green B>congo red>malachite green>acid fuchsin in the straw solid-state fermentation medium, but the strain PCu-9 had the better decolorization than the original strain; The strain PCu-9 had the same decolorization efficiency as the original strain in the wood flour solid-state fermentation medium, too. Both for naphthol green B>congo red>acid fuchsin>malachite green, but the strain PCu-9 had the better decolorization than the original strain,too. The strain PCu-9 decolorization efficiency was different from the original strain in the sugarcane bagasse solid-state fermentation medium.The strain PCu-9 is: naphthol green B>congo red>acid fuchsin>malachite green, the original strain is:congo red>naphthol green B>acid fuchsin>malachite green, but the strain PCu-9 had the better decolorization than the original strain; For congo red and acid fuchsin, the strain PCu-9 had the best decolorization ability when it was cultured in the sugarcane bagasse solid-state fermentation medium, the decolorization efficiency could respectively reach 95.69% and 88.70%; For naphthol green B and malachite green, the strain PCu-9 had the best decolorization when it was cultured in the straw solid-state fermentation medium, the decolorization efficiency could respectively reach 100% and 72.35%.